TW201641200A - Method for arc-welding molten Zn plated steel plate, method for manufacturing welded member, and welded member, each excellent in appearance of welded part and in welding strength - Google Patents

Abstract

When melting Zn-based plated steel sheet by means of arc welding, the process is carried out using pulse current waveforms with averaged welding current of 100~350A, averaged welding voltage of 20~35V, and the pulse period of current waveform is 1~50ms, which is repeated with perform peak current and base current; and the plated layer of the melted Zn-based plated steel sheet is mainly composed of Zn, in addition to Al of 1.0 ~ 22.0% by mass, and the electroplating adhesion amount W is 15 ~ 250g/m2.

Description

Arc welding method of molten Zn-based plated steel sheet having excellent weld portion appearance and welding strength, manufacturing method of welding assembly, and welding assembly

The present invention relates to an arc welding method, a method of manufacturing a welded component, and a welded component of a molten Zn-based plated steel sheet having an excellent weld portion appearance and weld strength, which are capable of reducing the amount of sputtering and pore generation.

The molten Zn-based plated steel sheet is used in a wide range of applications mainly for building components or automobile components because of its good corrosion resistance. Among these, the molten Zn-Al-Mg-based plated steel sheet containing the Al concentration of 1% by mass or more has an excellent corrosion resistance over a long period of time, and the demand for the conventional molten Zn-plated steel sheet is continuously increased. Moreover, the Al concentration in the plating layer of the conventional molten Zn-plated steel sheet is usually 0.3% by mass or less (refer to JIS G3302).

When a molten Zn-based plated steel sheet is used in a building component, an automobile component, or the like, it is often combined by an arc welding method. However, when the arc-welded Zn-based plated steel sheet is arc-welded, sputtering, dents, and pores (hereinafter, dents are included as long as pores are not particularly described) are generated, and the arc welding property is deteriorated. This is because Zn has a boiling point of about 906 ° C lower than the melting point of Fe of about 1538 ° C, so that Zn vapor is generated during arc welding, and the arc becomes unstable due to the Zn vapor, and sputtering occurs. Further, when the Zn vapor has not been discharged, if the molten pool is solidified, pores are generated. If the sputtering adheres to the plating surface, not only the appearance of the welded portion is poor, but also since this portion becomes a starting point of corrosion, the corrosion resistance is deteriorated. On the other hand, if the generation of the pores is conspicuous, there is a problem that the welding strength is deteriorated.

More specifically, in a module requiring long-term durability, a molten Zn-based plated steel sheet having a thickness per unit weight of 120 g/m ² or more is used, but a thick basis weight is used for Zn during arc welding. As the amount of vapor increases, the generation of sputtering and pores becomes more remarkable.

As a method of suppressing sputtering and pores of a molten Zn-based plated steel sheet, a pulse arc welding method has been proposed. According to the pulse arc welding method, small granulation droplets are used to suppress sputtering. Further, by the pulse arc, while stirring the molten pool, the molten pool is pressed down, the molten pool is thinned, and the detachment of Zn vapor is promoted, so that the pores are suppressed.

For example, Patent Document 1 discloses a pulse arc welding method in which the peak current, the peak time, and the base current of the wire composition and the pulse current waveform are controlled within an appropriate range to suppress sputtering and pores.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 9-206984

However, Patent Document 1 only discloses an example of a thin unit area weight molten Zn plated steel sheet having a plating adhesion amount of 45 g/m ² per surface, and does not describe sputtering or pores of a molten Zn-based plated steel sheet having a thick basis weight. The method of suppression.

Further, in Patent Document 1, a molten Zn plated steel sheet having an Al concentration in the plating layer of usually 0.3% by mass or less is used as a welding target. Since the Al concentration causes a difference in the melting point of the plating layer, the Al concentration in the plating layer affects the performance of the plating layer during soldering. Therefore, the technique of Patent Document 1 cannot be applied to a molten Zn-based plated steel sheet (for example, a molten Zn-Al-Mg-based plated steel sheet) having an Al concentration of 1% by mass or more.

As described above, the molten Zn-based plated steel sheet containing the Al concentration of 1% by mass or more has excellent corrosion resistance. However, during arc welding, sputtering and pores are generated, and the appearance and weld strength of the welded portion are deteriorated. In view of the above circumstances, an object of the present invention is to provide an arc welding method and a welding assembly including a molten Zn-based plated steel sheet having an excellent weld portion appearance and weld strength and having an Al concentration of 1% by mass or more.

According to the detailed research results of the inventors, it is known that the arc welding of the molten Zn-based galvanized steel containing Al having a concentration of 1% by mass or more is performed by the pulse arc welding method because the average welding current, the average welding voltage, the pulse period, Since the Al concentration and the plating adhesion amount in the plating layer are controlled within an appropriate range, the present invention can be completed without impairing the appearance of the welded portion and suppressing sputtering and pores.

In the arc welding method of the molten Zn-based plated steel sheet according to the present invention, the composition of the plating layer of the molten Zn-based plated steel sheet is mainly composed of Zn, and contains Al: 1.0 to 22.0% by mass, and the plating adhesion amount W is 15 to 250 g/m. ² ; and the average welding current is 100~350A, the average welding voltage is 20~35V, and the current waveform of the welding current is the pulse current waveform of the peak current and the base current repeatedly in the pulse period of 1~50ms for arc welding. .

According to the present invention, it is possible to provide a welded assembly capable of suppressing sputtering and pores during arc welding of a molten Zn-based plated steel sheet, and having excellent weld appearance, weld strength, and corrosion resistance.

1,1'‧‧‧Fused Zn plating plate

2‧‧‧welding line

3‧‧‧melting pool

4‧‧‧ pulse arc

5‧‧‧fusion

6‧‧‧weld

7‧‧‧Area

FIG. 1 is a schematic view showing a pulse current waveform and a pulse voltage waveform.

[Fig. 2] is a schematic view showing a phenomenon of pulse arc welding.

Fig. 3 is a view for explaining a method of measuring the amount of sputter adhesion and a definition of pore occupancy.

Fig. 4 is a view showing a lower limit value of an appropriate Al concentration in the plating layer of the present invention.

[Fig. 5] is a graph showing that an additive element affects the viscosity of Fe.

FIG. 1 is a schematic diagram showing current waveforms and voltage waveforms in a pulse arc welding method. The pulse arc welding method is an arc welding method in which the peak current IP and the base current IB are alternately repeated, and the peak current IP is set above the critical current of the droplet injection transition. In the case where the peak current IP is above the critical current, according to the contraction effect of the electromagnetic force, the droplets at the front end of the wire are shrunk to granulate the droplets, and a regular droplet transfer is performed every pulse period to cause the sputtering to be performed. inhibition. On the other hand, in the case where the peak current IP is equal to or lower than the critical current, since the droplet transition becomes irregular and the droplet greatly grows, the molten pool is short-circuited to cause sputtering.

Fig. 2 shows a schematic view of the welding phenomenon in the pulse arc welding method. In the pulse arc welding, since the small droplets 5 are ejected from the bonding wire 2 to the molten pool 3, no short circuit occurs, and sputtering is suppressed. Further, since the molten pool 3 directly under the arc is pressed by the pulse arc 4 to be thinned, the Zn vapor is easily discharged, so that the pores are suppressed.

However, in the case of a thick basis weight material having a large amount of plating adhesion, since the amount of Zn vapor generated is increased, even in the pulse arc welding method, Zn vapor is not discharged from the molten pool and stays in the molten pool, which is liable to occur. Stomata. Further, the Zn vapor remaining in the molten pool is ejected in one breath to disturb the arc, and sputtering is likely to occur. In the present invention, the average welding current, the average welding voltage, and the pulse period are controlled within an appropriate range, and the adhesion of the plating deposit and the Al concentration of the plating layer are appropriately managed to reduce the viscosity of the molten pool and promote The discharge of Zn vapor suppresses sputtering and pores.

The Mg concentration of the plating layer was fixed at 3% by mass, and the Al concentration was changed to 1 to 22% by mass. A sample of the molten Zn-based plated steel sheet having a plating adhesion amount of 15 to 250 g/m ² per one surface was prepared in the laboratory. Further, the sample size was a plate thickness of 3.2 mm, a width of 100 mm, and a length of 200 mm. The lap joint of this sample was 30 mm, and the fillet fillet was welded with a bead length L = 180 mm. Here, the average welding current is set to 100 to 350 A, the average welding voltage is 20 to 35 V, and the pulse period is set to 1 to 50 ms, and pulse arc welding is performed to produce a welded joint in which molten Zn-based plated steel sheets are joined to each other. The X-ray penetrating photograph of the arc welding portion is photographed, as shown in Fig. 3, and the pore length d ₁ ~ di along the long side direction of the bead 6 is measured, and the total value Σ di (mm) is obtained, and the formula (2) is obtained. ) Calculate the porosity occupancy Br. Further, the number of sputter adhesions in the region 7 having a width of 100 mm and a length of 100 mm centered on the bead 6 shown by the broken line in Fig. 3 was visually calculated. The region 7 is a square region having a length of 100 mm on each side surrounded by two sides of the bead 6 in the longitudinal direction of the bead 6 and the bead 6 at the center thereof and two sides perpendicular to the longitudinal direction of the bead 6.

Br = (Σdi / L) × 100 (2).

Fig. 4 shows the results of investigations on the influence of the Al concentration and the plating adhesion amount in the plating layer on the pore occupancy ratio Br and the number of sputter adhesion. According to the design of the welded joints for construction sheets - the construction manual (the construction of the thin-plate welded joints for construction - the construction manual compilation committee), as long as the porosity of the pores is less than 30%, the welding strength is not problematic. Further, as long as the number of sputter adhesions is 20 or less, the sputtering is not conspicuous, and the influence on the corrosion resistance is small. Here, in FIG. 4, the porosity occupancy rate is 30% or less, and the number of sputtering adhesions is 20 or less, and is plotted as ○, and the case where the pore occupancy ratio exceeds 30% or the sputtering adhesion amount exceeds 20 is plotted as ●. In the region surrounded by the four straight lines in Fig. 4, the pore occupancy ratio Br is 30% or less and the number of sputtering adhesions is 20 or less. Therefore, it is known that sputtering and pores can be suppressed by appropriately managing the plating adhesion amount and the Al concentration. .

That is, as shown in FIG. 4, the average welding current is set to 100 to 350 A, the average welding voltage is 20 to 35 V, and the pulse period is set to 1 to 50 ms, and pulse arc welding is performed to have an Al concentration of 1 to 22 mass. A molten Zn-based plated steel sheet having a plating layer of 15 to 250 g/m ² per 100% of the plating layer can suppress sputtering and pores.

Further, in Fig. 4, in the case where the Al concentration C _Al (% by mass) and the plating adhesion amount W (g/m ² ) in the plating layer satisfy the range of C _Al < 0.0085 + 0.87, although it is shown that the pores are When the occupancy rate exceeds 30% or the amount of sputter deposition exceeds 20, the average welding current, the average welding voltage, and the pulse arc welding conditions other than the pulse period are appropriately adjusted, thereby suppressing the porosity of 30% or less and sputtering adhesion. The number is less than 20. In other words, when the plating adhesion amount is 15 to 250 g/m ² , in order to suppress the porosity occupancy rate of 30% or less and the number of sputtering adhesions to 20 or less, in the range of C _Al <0.0085 W + 0.87, in addition to the average welding current and average. For the welding voltage and pulse period, it is necessary to adjust the welding speed and shielding gas composition other than these. In the range of 0.0085 + 0.87 ≦ C _Al , the average welding current, the average welding voltage, and the pulse period are adjusted. Therefore, in order to suppress the porosity occupation ratio of 30% or less and the number of sputter adhesions to 20 or less, it is preferably in the range of 0.0085 W + 0.87 ≦ C _Al .

The pulse arc welding conditions of the present invention are described in detail below.

[average welding current]

In the present invention, the current waveform shown in Fig. 1 is a pulse waveform in which the peak current and the base current are repeated, and the average welding current IA is preferably in the range of 100 to 350 Å. In the present invention, the average welding current IA is as shown in the following formula (3).

IA=((IP×TIP)+(IB×TIB))/(TIP+TIB)...(3)

among them,

IP: peak current (A)

IB: base current (A)

TIP: peak current period (ms)

TIB: base current period (ms)

When the average welding current is less than 100 A, the heat input is insufficient, the temperature of the molten pool is lowered, the viscosity is increased, the Zn vapor is difficult to be discharged, and Zn vapor remains in the molten pool to cause pores. When the welding current is connected to the supply amount of the bonding wire, if the welding current is increased to a demand or higher, since the droplet is coarsened and the molten pool is short-circuited to cause sputtering, the welding current is preferably 350 A or less.

[average welding voltage]

In the present invention, the average welding voltage EA is preferably in the range of 20 to 35V. In the present invention, the average welding voltage EA is as shown in the following formula (4).

EA=((EP×TEP)+(EB×TEB))/(TEP+TEB)...(4)

among them,

EP: peak voltage (V)

EB: base voltage (V)

TEP: peak voltage period (ms)

TEB: base voltage period (ms)

When the average welding voltage EA is lower than 20 V, the arc length becomes short, and the droplets are short-circuited with the molten pool to cause sputtering. If the average welding voltage exceeds 35V, burn-through will occur due to excessive heat input.

[pulse period]

The pulse period PF is in the range of 1 to 50 ms. Below 1 ms, the droplet transition becomes unstable and sputtering occurs. On the other hand, if it exceeds 50 ms, the period in which the arc does not occur becomes too long, the effect of the pressing of the molten pool becomes weak, and the Zn vapor becomes difficult to be discharged, and sputtering and pores are generated.

[welding speed]

The welding speed in the present invention is not particularly limited. It is appropriately selected depending on the thickness of the plate of the molten Zn-based plated steel sheet.

[masking gas]

In the pulse arc welding method, an Ar-CO ₂ mixed gas is used for the droplet ejection transition. The shielding gas in the present invention is also an Ar-CO ₂ mixed gas. Ar-30 vol% CO ₂ gas or Ar-20 vol% CO ₂ gas or Ar-5 vol% CO ₂ gas having a lower CO ₂ concentration is preferable because the sputtering suppression effect is large.

[Fused Zn-based plated steel sheet]

In the molten Zn-based plated steel sheet according to the present invention, the composition of the plating layer is mainly composed of Zn, and contains Al: 1.0 to 22.0% by mass, and the plating adhesion amount W is 15 to 250 g/m ² .

Further, it is preferable that the plating adhesion amount W and the Al concentration C _Al in the plating layer satisfy the relationship of the following formula (1).

0.0085W+0.87≦C _Al ≦22...(1)

among them,

W: plating adhesion amount (g/m ² )

C _Al : Al concentration (% by mass) in the plating layer.

The plating layer of the molten Zn-based plated steel sheet may further contain Mg: 0.05 to 10.0% by mass, Ti: 0.002 to 0.10% by mass, B: 0.001 to 0.05% by mass, Si: 0 to 2.0% by mass, and Fe: 0 to 2.5. At least one of the groups consisting of % of mass.

Although the method of the melt plating is not particularly limited, in general, the use of an in-line annealing type molten plating apparatus is advantageous in terms of cost. The composition of the plating layer is a substance that substantially reflects the composition of the molten plating bath. Hereinafter, the constituent elements of the plating layer will be described. "%" of the plating component elements means "% by mass" unless otherwise stated.

Al has an effect of improving the corrosion resistance of the plated steel sheet, and in the plating bath, generation of Mg oxide slag is suppressed. Further, as shown in FIG. 5, Al is added in a small amount to reduce the viscosity of Fe. During arc welding, Al in the plating layer enters the molten pool, lowers the viscosity of the molten pool, and promotes the discharge of Zn vapor to suppress Sputtering, pores. In order to fully exert these effects, it is necessary to ensure an Al content of 1.0% or more, and it is preferable to ensure an Al content of 4.0% or more. On the other hand, if The Al content is increased, and a brittle Fe-Al alloy layer is easily formed at the bottom of the plating layer, and excessive formation of the Fe-Al alloy layer is a cause of a decrease in plating adhesion. Based on the results of various reviews, the Al content is preferably 22.0% or less, and may be managed at 15.0% or less or even 10.0% or less.

Mg uniformly forms a corrosion product on the surface of the plating layer, and exhibits a remarkable effect of improving the corrosion resistance of the plated steel sheet. It is more effective to have a Mg content of 0.05% or more, and a Mg content of 1.0% or more is more effective. On the other hand, when the Mg content in the plating bath is increased, the Mg oxide-based slag is likely to be generated, and the quality of the plating layer is lowered. Therefore, the Mg content should be in the range of 10.0% or less. Further, Mg has a boiling point of about 1091 ° C and is lower than the melting point of Fe. Like Zn, it evaporates during arc welding. Since it is considered to cause sputtering and pores, the Mg content is desirably 10.0% or less.

When Ti is contained in the molten electroplating bath, the formation and growth of the Zn ₁₁ Mg ₂ -based phase which deteriorates the appearance of the plating layer and the corrosion resistance are suppressed, so that the effect is preferable. When the amount of addition of Ti is less than 0.002%, the effect of suppressing is insufficient. When the amount is more than 0.1%, the formation and growth of precipitates of Ti-Al type are caused during plating, which causes a defect in the appearance of the surface of the plating layer. Therefore, in the present invention, the amount of Ti added is limited to 0.002 to 0.1%.

B is also the same as Ti, and has an effect of suppressing the formation and growth of the Zn ₁₁ Mg ₂ -based phase. In the case of B, the addition amount is 0.001% or more. However, if B is excessively added, since Ti-B or Al-B-based precipitates are caused, the appearance of the surface of the plating layer is poor, so B is preferably in the range of 0.05% or less.

When Si is contained in the molten electroplating bath, excessive growth of the Fe-Al alloy layer formed at the interface between the surface of the plated substrate and the plating layer is suppressed, and it is advantageous in terms of improving the workability of the molten Zn-Al-Mg-based plated steel sheet. of. Therefore, Si can be contained as necessary. In this case, it is effective to have a Si content of 0.005% or more. However, because it contains excessive Si, it is added to the molten electroplating bath. The main reason for the amount of slag is that the Si content is preferably 2.0% or less.

In the molten electroplating bath, Fe is easily mixed because of the relationship between the impregnation and passage of the steel sheet. When Fe is mixed in the Zn-Al-Mg-based plating layer, the Fe content is preferably 2.5% or less because the corrosion resistance is lowered.

[Electroplating adhesion]

If the amount of plating adhesion of the molten Zn-Al-Mg-based plated steel sheet is small, it is disadvantageous for maintaining the corrosion resistance and the sacrificial anti-corrosion effect of the plating surface for a long time. Based on the results of various reviews, it is effective to have a plating adhesion amount of 15 g/m ² or more per one side. On the other hand, when the plating adhesion amount exceeds 250 g/m ² , the amount of Zn vapor generated is too large, and even in the present invention, it is difficult to suppress sputtering and pores, so the upper limit is 250 g/m ² .

[Pore occupancy, number of sputter adhesions]

According to the design of the welded joints for construction sheets - the construction manual (the construction of the thin-plate welded joints for construction - the construction manual compilation committee), as long as the measured value of the total value of the pores Σdi (mm) is as shown in Fig. 3 The porosity occupancy ratio Br calculated by the formula (2) is 30% or less, and the welding strength is not problematic. The welded component of the present invention has an air hole occupancy ratio Br of 30% or less and has excellent welding strength.

Br=(Σdi/L)×100...(2)

Σdi: total value of pore length (mm)

L: weld bead length (mm).

As shown by the broken line in Fig. 3, as long as the number of sputter adhesions in the region 7 having a width of 100 mm and a length of 100 mm as the center of the bead is 20 or less, the sputtering is not conspicuous, and the influence on the corrosion resistance is small. The welded component of the present invention has an adhesion amount of 20 or less, and has an excellent weld appearance and corrosion resistance.

As described above, in the arc welding method of the molten Zn-based plated steel sheet according to the present embodiment, the composition of the plating layer of the molten Zn-based plated steel sheet contains Zn as a main component and contains Al: 1.0 to 22.0% by mass, and the plating adhesion amount W is 15~250g/m ² ; and the average welding current is 100~350A, the average welding voltage is 20~35V, and the current waveform of the welding current is the pulse current waveform of the peak current and the base current repeatedly in the pulse period of 1~50ms. , to perform arc welding.

Further, in the arc welding method of the molten Zn-based plated steel sheet according to the present embodiment, the plating adhesion amount W (g/m ² ) of the molten Zn-based plated steel sheet and the Al concentration C _Al (% by mass) in the plating layer are preferably The relationship of the following formula (1) is satisfied.

0.0085W+0.87≦C _Al ≦22...(1)

Further, in the arc welding method of the molten Zn-based plated steel sheet according to the present embodiment, the plating layer of the molten Zn-based plated steel sheet may further contain Mg: 0.05 to 10.0% by mass, Ti: 0.002 to 0.10% by mass, and B: 0.001%. At least one of a group consisting of 0.05% by mass, Si: 0 to 2.0% by mass, and Fe: 0 to 2.5% by mass.

In the arc welding method of the molten Zn-based plated steel sheet according to the present embodiment, arc welding is performed so that the pore occupancy ratio Br represented by the following formula (2) is 30% or less, and the weld bead is centered at a length of 100 mm. The number of sputter adhesions in a region having a width of 100 mm is 20 or less.

Br=(Σdi/L)×100...(2)

among them,

Di: to observe the length of the i-th pore

L: is the length of the weld bead.

Further, in the method for producing a welded component according to the present embodiment, the composition of the plating layer is mainly composed of Zn, and the molten Zn-based plated steel sheet containing Al: 1.0 to 22.0% by mass is joined by arc welding; The adhesion amount W of each single side of the plated steel plate is 15~250g/m ² ; and the average welding current is 100~350A, the average welding voltage is 20~35V, and the current waveform of the welding current is pulse period of 1~50ms. The pulse current waveforms of the peak current and the base current are repeatedly performed to arc-weld the molten Zn-based plated steel sheets.

In the welding module of the present invention, the composition of the plating layer is mainly composed of Zn, and the molten Zn-based plated steel sheets containing Al: 1.0 to 22.0% by mass are welded to each other, and the molten Zn-based plating is performed. The adhesion amount W of each single side of the steel sheet is 15 to 250 g/m ² , and the pore content Br is 30% or less; and the number of sputtering adhesions in the region having a bead center of 100 mm and a width of 100 mm is 20 or less. Excellent weld appearance and corrosion resistance.

[Examples]

A cold-rolled steel strip having a thickness of 3.2 mm and a width of 1000 mm was used as a plating substrate, and this was transported to a melt-plating line to produce a molten Zn-Al-Mg-based plated steel sheet.

A sample having a width of 100 mm and a length of 200 mm was cut out from the above-mentioned plated steel sheet, and pulsed arc welding was performed by overlapping the fillet welded joint. The welding line used JIS Z3312 YGW12, the welding speed was 0.4 m/min, the bead length was 180 mm, and the lap joint was 30 mm. Other welding conditions are shown in Tables 1 and 2. After the pulse arc welding, X-rays were taken through the photograph, and the porosity occupancy Br was measured by the aforementioned method. Moreover, the amount of sputter adhesion was measured by visual inspection.

In Table 1, an embodiment of the pulsed arc welding of the present invention is shown. Further, in Table 2, a reference example in which the Al concentration C _Al (% by mass) and the plating adhesion amount W (g/m ² ) in the plating layer are in the range of C _Al < 0.0085 W + 0.87 is shown, and is shown in the plating layer. A comparative example in which the Al concentration was subjected to pulse arc welding outside the range of the conditions of the present invention.

As shown in Nos. 1 to 30 of Table 1, in the examples in which the pulse arc welding conditions and the Al concentration in the plating layer are within the range of the present invention, the porosity occupancy rate is 30% or less, and the sputtering adhesion amount is 20 or less. . According to the present embodiment, according to the present invention, it is possible to obtain an excellent appearance of a welded portion, A Zn-Al-Mg-based galvanized steel 钣-arc welding assembly with corrosion resistance and weld strength.

As shown in Nos. 31 to 34 of Table 2, in the reference example in which the Al concentration C _Al (% by mass) and the plating adhesion amount W (g/m ² ) in the plating layer are in the range of C _Al < 0.0085 + 0.87 Found sputter and pores. However, in the range where C _Al <0.0085W+0.87 is satisfied, by appropriately adjusting the average welding current, the average welding voltage, and the pulse arc welding conditions other than the pulse period, the porosity occupancy can be suppressed to 30% or less, and the sputtering adhesion can be suppressed. The number is less than 20.

In contrast, in the comparative examples in which the average welding current, the average welding voltage, and the pulse period of No. 35 to 39 were out of the range of the present invention, sputtering and pores were remarkably generated. Further, in the comparative example in which the plating adhesion amount of No. 40 exceeded the range of the present invention, sputtering and pores were also apparent.

Claims (6)

An arc welding method for a molten Zn-based plated steel sheet is an arc of a molten Zn-based plated steel sheet in which a composition of a plating layer is mainly composed of Zn and a molten Zn-based plated steel sheet of Al: 1.0 to 22.0% by mass is bonded to each other. The welding method comprises: the adhesion amount W of each one side of the molten Zn-based plated steel plate is 15 to 250 g/m ² ; and the average welding current is 100 to 350 A, and the average welding voltage is 20 to 35 V, and the current of the welding current The waveform is a pulse current waveform in which a peak current and a base current are repeatedly performed in a pulse period of 1 to 50 ms to perform arc welding. The arc welding method of the molten Zn-based plated steel sheet according to claim 1, wherein the plating adhesion amount W (g/m ² ) of the molten Zn-based plated steel sheet and the Al concentration C _Al (% by mass) in the plating layer satisfy the following formula Relationship of (1): 0.0085 W + 0.87 ≦ C _Al ≦ 22 (1). The arc welding method of the molten Zn-based plated steel sheet according to claim 1 or 2, wherein the composition of the plating layer of the molten Zn-based plated steel sheet further contains Mg: 0.05 to 10.0% by mass, Ti: 0.002 to 0.10% by mass, B At least one of the group consisting of 0.001 to 0.05% by mass, Si: 0 to 2.0% by mass, and Fe: 0 to 2.5% by mass. The arc welding method of the molten Zn-based plated steel sheet according to claim 1 or 2 is subjected to arc welding so that the pore occupancy ratio Br represented by the following formula (2) is 30% or less; and the length of the weld bead is 100 mm. The number of sputter adhesions in the region of 100 mm in width is 20 or less; Br = (Σdi / L) × 100 (2); wherein di: is the length of the i-th pore; L: is the length of the weld bead. A method for producing a welded component is a method of manufacturing a welded component in which a composition of a plating layer is mainly composed of Zn and a molten Zn-based plated steel sheet of Al: 1.0 to 22.0% by mass is bonded to each other by arc welding. The method comprises the following: the adhesion amount W of each one surface of the molten Zn-based plated steel plate is 15 to 250 g/m ² ; and the average welding current is 100 to 350 A, the average welding voltage is 20 to 35 V, and the current waveform of the welding current is 1 The pulse current waveform of the peak current and the base current is repeated in a pulse period of ~50 ms to arc-weld the molten Zn-based plated steel sheets. A welded component of a molten Zn-based plated steel sheet is a welded component obtained by welding a molten Zn-based plated steel sheet having a composition of a plating layer of Zn as a main component and containing Al: 1.0 to 22.0% by mass, comprising: The adhesion amount W of each one surface of the molten Zn-based plated steel sheet is 15 to 250 g/m ² ; the porosity of Br of the following formula (2) is 30% or less; and the length of the weld bead is 100 mm and the width is 100 mm. The number of sputter adhesions in the region is 20 or less; Br = (Σdi / L) × 100 (2); wherein di: is the length of the i-th pore; and L: is the length of the bead.